feat(lab): add recorded realtime spatial playback

tests/test_m4_threat_replay_result.py

@@ -16,6 +16,7 @@ RESULTS_ROOT = REPOSITORY_ROOT / ".runtime/compute-experiments/m4/replay-threat"
 def _endpoint(path: str, *, camera_frame_provider=None):
     router = build_m4_threat_replay_router(
         root_provider=lambda: RESULTS_ROOT,
+        repository_root_provider=lambda: REPOSITORY_ROOT,
         camera_frame_provider=camera_frame_provider,
     )
     return next(
@@ -120,16 +121,28 @@ def test_m4_6_lab_api_projects_report_and_exact_visual_frame() -> None:
     }
 
 
-def test_m4_6_video_overlay_covers_the_exact_recorded_camera_timeline() -> None:
-    get_overlay = _endpoint("/api/v1/laboratory/m4-threat/results/{result_id}/video-overlay")
+def test_m4_6_timeline_is_indexed_and_spatial_evidence_is_chunked() -> None:
+    get_timeline = _endpoint("/api/v1/laboratory/m4-threat/results/{result_id}/timeline")
+    get_chunk = _endpoint("/api/v1/laboratory/m4-threat/results/{result_id}/timeline/chunk")
 
-    overlay = get_overlay(RESULT_ID)
+    timeline = get_timeline(RESULT_ID)
+    assert timeline["schema_version"] == "missioncore.recorded-spatial-evidence-timeline/v1"
+    assert timeline["frame_count"] == 4489
+    assert len(timeline["frame_times_ns"]) == 4489
+    assert timeline["recorded_source"]["session_id"] == "20260720T065719Z_viewer_live"
+    assert "frames" not in timeline
 
-    assert overlay["frame_count"] == 4489
-    assert overlay["recorded_source"]["session_id"] == ("20260720T065719Z_viewer_live")
-    assert overlay["frames"][0]["frame_index"] == 0
-    assert overlay["frames"][-1]["frame_index"] == 4488
-    assert overlay["authority"] == "replay-simulated"
+    chunk = get_chunk(RESULT_ID, start=1880, count=12)
+    assert chunk["schema_version"] == "missioncore.recorded-spatial-evidence-chunk/v1"
+    assert chunk["start_sequence"] == 1880
+    assert chunk["frame_count"] == 12
+    assert [frame["sequence"] for frame in chunk["frames"]] == list(range(1880, 1892))
+    first = chunk["frames"][0]
+    assert first["schema_version"] == "missioncore.recorded-spatial-evidence-frame/v1"
+    assert first["spatial_available"] is True
+    assert first["point_cloud_layer"] == "current-increment"
+    assert 0 < first["point_cloud_sample_count"] <= 2000
+    assert first["camera_url"].endswith(f"/{RESULT_ID}/timeline/frames/1880/camera")
 
 
 def test_m4_6_exact_camera_endpoint_is_bound_to_selected_visual_sequence() -> None:
@@ -155,3 +168,26 @@ def test_m4_6_exact_camera_endpoint_is_bound_to_selected_visual_sequence() -> No
     assert response.media_type == "image/jpeg"
     assert response.headers["etag"] == f'"{"a" * 64}"'
     assert calls == [("20260720T065719Z_viewer_live", 2584)]
+
+
+def test_m4_6_timeline_camera_endpoint_is_bound_to_exact_sequence() -> None:
+    calls: list[tuple[str, int]] = []
+
+    def provide(session_id: str, frame_index: int) -> RecordedCameraFrame:
+        calls.append((session_id, frame_index))
+        return RecordedCameraFrame(
+            payload=b"timeline-jpeg",
+            media_type="image/jpeg",
+            width=800,
+            height=600,
+            sha256="b" * 64,
+        )
+
+    endpoint = _endpoint(
+        "/api/v1/laboratory/m4-threat/results/{result_id}/timeline/frames/{sequence}/camera",
+        camera_frame_provider=provide,
+    )
+    response = endpoint(RESULT_ID, 2584)
+
+    assert response.body == b"timeline-jpeg"
+    assert calls == [("20260720T065719Z_viewer_live", 2584)]